Alaska earthquakes

M3.3 earthquake 233 km WSW of Adak, Alaska

A magnitude 3.3 earthquake struck 233 km WSW of Adak, Alaska on Wed, Aug 11, 2021, 5:23 PM HADT (02:23 UTC), 65 km (40 mi) below the surface.

A larger quake followed: M6.1 187 km WSW of Adak, Alaska. This one was a foreshock.

Map

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The earthquake

Magnitude: 3.3 (ml), minor
Local time: Wed, Aug 11, 2021, 5:23 PM HADT
UTC: 2021-08-12 02:23:59 UTC
Depth: 65.1 km (40.5 mi), shallow
Epicenter: 51.467° N, 179.949° W
Region: Alaska
Tsunami flag: No
Status: Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.9 km horizontally, 7.8 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 177°
Stations used: 47

Nearby

Within 100 km, magnitude 1.5 and up: 146 in the 60 days after this one and 63 in the 30 days before it.

After

The first 60 of 146.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000f2tq (also filed as ak021aahpnwu). Read Thu, Sep 24, 2026, 12:05 PM UTC.